Washington, Dec 3 : It can be really difficult to gauge a person's mood by analysing his facial expression, but an Indian-origin scientist is now developing an image processing system that could tell your mood just by looking at the face.

Dr. Prabir Bhattacharya in collaboration with Concordia graduate student Abu Sayeed Sohail is working on a computer image processing system that detects and classifies human facial expressions. The system is aimed to take and analyze photos of individuals, potentially in areas of high traffic where security is a primary concern, such as an airport.

If it's possible to take random photos of the crowd and process them fast enough, one could potentially identify problematic individuals.

In fact, facial expressions do not actually involve the entire face, but instead specific sets of muscles under the face near the eyes, nose and mouth.

Bhattacharya and Sohail's system measures 15 key points on the face and then compares these measures against images of identifiable facial expressions.

While there is great variety in expression across both individuals and cultures, the pair has identified seven basic expressions that seem to be relatively universal.